I am trying to plan my first garden - using "John Jeavons' How to grow more vegetables" as my guide.

Here are some questions I have -
1. When should I order seed potato (every web site I check says they are sold out, so I am guessing they come in the spring). If you have recommendations on some good sources will be nice.
2. The plan in the book, suggests I start many items indoors, got that, but the schedule for starting them varies, some are started after the weather has warmed. The question is - do the flats where I start after the weather has warmed have to go under the lights and on a warming mat etc. (Just trying to see how much space I need to have with the lights).
3. Onion sets - is it better to wait for them to be available in the local garden centers or order them online? Same question for shallots as well.
3. Any tips / advice you all can give, please I will gladly accept.

Thank you very much.

1) I've noticed seed potatoes in the local Rural King in the spring. If you have a local farm supply type store or a good local garden center, perhaps try there. Since potatoes are heavy, I am guessing the shipping costs would be high (but worth it if you want a certain type of potato).

2) If the outside soil temperature is warm enough, many seeds can be direct sowed. Some veggies take a long time to produce (peppers, tomatoes, etc) so it helps to start them early indoors. Indoor lighting is almost never bright enough... 16 hours under your grow lights helps but plants still need to adjust to direct sun gradually. I find many seeds germinate without extra heat. However, pepper seeds and basil seeds germinate much better & faster with some heating (warmer soil). Peppers can take 2 or 3 weeks to germinate with heating... and never germinate without. Last time I tried basil without heat, zip.

Damping off can be a big problem when germinating seeds indoors. I like to put a slow speed house fan on a timer and have it come on periodically (for 1/2 hour every 2 or 3 hours). You just want to seem them vibrate a little in the breeze. The fan also helps strengthen the small plants so they can handle wind when they get planted outside.

3) Onions (and I assume shallots) are cool weather crops and can get in the ground early. I have not tried sets. I have been starting onions from seed (maybe 2 months before they get planted out). It gets old taking care of them that long, but they are good come harvest time! I don't recall seeing shallots sets locally... You may want to mail-order them to make sure you get some. But I would think you could find onion sets at several places locally.

4) It's one big experiment! You learn by doing. Hopefully your book mentioned cool weather crops and warm weather crops. If not, research it on the web. But by all means, enjoy!

Many grocery stores stock seed potatoes and onion sets in spring. They will cost least if you buy in bulk and split a large order with friends or neighbors. One other thing you can do is to select small potatoes from the open grocery bins and cut your own sets. Each potato will have several "eyes". Cut the pieces so there is one eye on each bit. Then lay them out to dry for a week or so. This will harden off the cut edges so they won't rot when you set them in the ground.